Fluid-actuated inlet valve for rock drills



Feb. 26 1924.

F. M. SLATER FLUID ACTUATED INLET VALVE FOR ROCK DRILLS Filed Oct. 21. 1922 INVENTOR flew- 95 HIS AEIEY Patented Feb. 26, T92 3.

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FRED M. SLATER, OF EASTON, PENNSYLVANIA, ASSIGNOB TO INGERSOLL-RAND COM- IANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

FLUID-ACTUATED INLET VALVE FOR ROCK DRILLS.-

application filed. October 21, 1922. Serial No. 595,885.

To all whom it may concern:

Be it known that I, FRED M. SLATER, a citizen of the United States, and a resident of Easton, county of Northampton, and 5 State of Pennsylvania, have invented a certain Fluid-Actuated Inlet Valve for Rock Drills, of which the following is a specifi cation accompanied by drawings.

This invention relates to fluid actuated rock drills, but more particularly to a fluid actuated valve, adapted to control the inlet supply, the main exhaust being controlled by the piston, although it is to be understood that anti-compression ports for-the cylinder may also be controlled by the valve. Machines having inlet valves of the usual type have been subject to the following difliculties: either the piston has been long and consisted of two at heads anda joiningneck, orelse it has been necessary to throw the valve by compresslon. a

The objects of the present invention, like those in myco-pendingapplication, Serial No. 520,344,-filed December 6, 1922, are to enable thevalve to bethrown by live air and utilize a piston having one head, thus decreasing the over-all length and weight of the machine,

Another important object of the inven tion, is to produce a valve of the reciprocating spool type having the minimum length of travel for the same-area of opening as in other valves, having considerably longer length of travel. By shortening the travel of the valve, thespeed of the valve may be increased, thus increasing theiefliciency ofthe machine. r .7

Further objects of the invention will here inafter appear, and to all of these ends the invention is, shown in the accompanying drawings, in which p Figure 1 is a longitudinal sectional elevation of a fluid actuated rockdrill having 5 my improved valve applied thereto,

Figure 2 is a detail longitudinal sectional elevation of a portion of themachine showing the valve in a different position from that indicated in Figure 1, and

Figure 3 is an enlarged detail longitudinal sectional viewtakenthrough the valve and valve chest. I

Referring to the drawings, the rock drill to. which my valve is applied, for purposes of illustration, comprises a cylinder A having a reciprocating piston B provided with a head C and a shank D adapted to impart blows of impact to the shankof the drill steel E extending into the chuck F in the front head G in position to be struck by the piston. A front cylinder extension H may be interposed between the cylinder and front headG and the parts may be held together by the usual side bolts, not shown.

In this instance, a rock drill having automatic rotationis illustrated, and the shank D of the piston is provided with the flutes J engaging the flutes K on the chuck F. A rifle bar L engages-the piston and extends through the back cylinder washer O and is formed with the usual ratchet]? cooperating with the rotation ratchet ring Q, over which is placed the back rotation washer R. A suitable handle S is connected to the rock drill in. any convenient manner.

A valve chest T is located at one side of the cylinder and motive fluid, in this instance, is supplied to the machine through the inlet U controlled by the usual throttle valve V having the handle W. Valve bushings X and Yare adapted to be inserted in the valve chest T and as a convenient construction, the bushing X is formed with the extensiona extending through one end of the valve chest and provided with a nut b for holding said bushingin the chest. The valve 0 is then inserted in the bushing X and the bushing Y having the flange d is then placed in the valve chest. A filler or washer e. preferably of soft material is placed over the head or flange b of the bushing Y and a plug f holds the parts in position.

The bushings X and Y are so constructed that the opposed edges gand h at the meeting faces of the bushings are separated by a space opposite the groove j in the valve chest, so that an annular inlet port is formed at this point opposite the inlet U. The valve 0 is formed with the end heads 70 and 0 and a central flange p of larger diameter than theiheads, which flange controls the passage of motive fluid from the inlet U to both ends of the cylinder A. The flange p as shown extends into the annular port between the meeting edges g and h of the valve bushings, and as the valve reciprocates, the said flange seats upon said meeting edges 9 and h which also form stops limiting the movement of the valve By this means the travel of the valve is reduced to a minimum with'the maximum port area desired for supply of motive fluid to the machine. 7

' The valve bushings X and Y are formed with the ports 9 and r registering with the ports 8 and t leading to the opposite ends of the cylinder, and valve actuating ports to and 7 are connected by passages 10 and m to the opposite ends of the valve for actuating it in opposite directions.

The valve is preferably shown hollow with a central web 3 through which small ports 2 and: 3 are conveniently locatedat an angle to the longitudinal axis of the valve, whichsmall ports-connect the inlet'U di rectly with the spaces 4: and 5 respectively at the ends of the valve.

The valve is thrown by live air, the fluid passing to the ends of the valve through the small ports 2 and 3,'and building up pressure-at one of the said ends of the valve, when the piston crosses one of the connect: ing passages to or m, the other of the said connecting passages being opened to atmos phere throughthe cylinder. The valve is held by the pressure of live motive fluid on one of the faces of the central flange p, which as stated, is of larger diameter than either head is or 0.

In the operation of the device, let it be assumed that the pistonB in Figure l is starting on its rearward stroke, the valve is in the position indicated in said figure, and live motive-fluid passes from the inlet U around the valve through the supply pas sage s to the frontof the cylinder, driving the piston rearwardly. The pressure of the motive fluid on the face ofthe central flange 29 holds the valveiin its rearward position, as indicated. Any leakage from the inlet past the forward head 0 of the valve only serves to vhold the valve in the desired'position. Motive fluid passing through the smallport 2 to the rearward end of the valve leaks to atmosphere through the connecting passage w, port o and the open main exhaust port 2 in the side of the cylinder A.

As the piston moves rearwardly, and uncovers the main exhaust e, as shown in Fig ure 2, the pressure holding the valve in its rearward position is reduced to atmosphere, both in front of the central flange 7) and behind the forward valve head 0. The exhaust from the rearward endof the cylinder having been closed by the piston, in its rearward movement,and the pistonhaving overrun the port 4) opening into the connecting passage 0;, the pressure of live motive fluid built up in front of therearward valve head is will cause the valve to bethrow'n forward 1y, thus openingthe supply of motive fluid to the rearward end of the cylinder, which starts the piston forwardly and at the same time the pressure on the rearward face of the central flange. p holds the valve in forward position.

When the valve is in the position indi cated in Figure 1, or as shown in the enlarged view of Figure 3, it will be observed that the small port 3 is cut off from'the inlet supply, and finally in the position indicated in Figure 2, the small port 2 is cut off from the inlet supply. This is the preferable construction, because if these small ports 2 and 3 are continuously open to the inlet supply," there would be a certain amount of waste motive fluid pass through the said ports to atmosphere through the open exhaust port, and the motive fluid would not be-alternately admitted to either end of the valve, although the valve would operate in substantially the same manner. If desired, the valve 0 need only control the inlet to both ends ofthe cylinder, but in the form shown I have indicated the valve as controlling cushion release or anti-compression ports 6 and 7 in the valve chest, communicating with the ports 8 and 9 in the bushings X-and Y respectively, which. ports are controlled by the heads is and 0 of the valve. V

I claim:

1. In a fluid actuated rock drill, the combination. with a cylinder and reciprocating piston, of a valve chest, a fluid actuated valve controlling the inlet supply and havingend heads and a single central flange of larger diameter than the heads, which flange controls the passage of motivefluid from the inlet to both endsof the cylinder, a central annular inlet port in said valve chest into which the central flange of the valve extends and seats and in which the said-flange reciprocates, theedges of saidannular port also forming stops for limiting the movement of the valve, small ports connecting the inlet directly with the spaces at the ends of the valve, connecting passages joining the spaces at each end of the valve with the cylinder at points between the middle andvthe ends of the cylinder, and a free exhaust-port controlled by the piston, whereby the valve is thrown by the live motive fluid passing to the ends of-the valve through said small ports and building up pressure at one of the said ends of the valvewhen the piston crosses one of said connecting passages, the other of said connecting passages being open to atmospherethrough the cylinder, and the valve being held by the pressure of live motive fluid on one face of the central flange of larger diameter than the heads of the valve. I I

2. In a fluidzactuated rock drill, the combination with the cylinder and reciprocating piston, of a valve chest, a fluid actuated valve controlling the inlet supply and hav ingendheads and a single central flange of larger diameter than the heads, which controls the passage of motive fluid from the inlet to both ends of the cylinder, a central annular inlet port in said valve chest, the edges of which form seats for the central flange of the valve and limit its movement in either direction, small ports connecting the inlet directly with the spaces at the ends of the valve, connecting passages joining the spaces at each end of the valve with the cylinder at points between the middle and ends of the cylinder, and a free exhaust port controlled by the piston, whereby the valve is thrown by the live motive fluid passing to the ends of the valve through said small ports and building up pressure at one of the said ends of the valve when the piston crosses one of said connecting passages, the other of said connecting passages being open to atmosphere through the cylinder, and the valve being held by the pressure of live motive fluid on one face of the central flange of larger diameter than the heads of the Valve.

In testimony whereof I have signed this 

